Ion implantation systems may include an ion source and a series of beam-line components. The ion source may comprise a chamber where ions are generated. The ion source may also comprise a power source and an extraction electrode assembly disposed near the chamber. The beam-line components may include, for example, a mass analyzer, a first acceleration or deceleration stage, a collimator, and a second acceleration or deceleration stage. Similar to a series of optical lenses for manipulating a light beam, the beam-line components can filter, focus, and manipulate ions or an ion beam to have an intended species, shape, energy, and/or other qualities. The ion beam passes through the beam-line components and may be directed toward a substrate mounted on a platen or clamp. The substrate may be moved in one or more dimensions (e.g., translate, rotate, and tilt) by an apparatus, sometimes referred to as a roplat.
The ion implantation system generates a stable, well-defined ion beam for a variety of different ion species and extraction voltages. After several hours of operation using source gases (such as AsH3, PH3, BF3, and other species), beam constituents eventually create deposits on beam optics. Beam optics within a line-of-sight of the wafer also become coated with residues from the wafer, including Si and photoresist compounds. These residues build up on the beam-line components, causing spikes in the DC potentials during operation (e.g., in the case of electrically biased components). Eventually, residues flake off, causing an increased likelihood of particulate contamination on the wafer.
One way to mitigate the effect of the material accumulation is to intermittently replace beam-line components of the ion implanter system. Alternatively, beam-line components may be manually cleaned. Yet, manually cleaning entails powering down the ion source and releasing the vacuum within the system. After replacing or cleaning the beam-line components, the system is then evacuated and powered to reach an operational condition. Accordingly, these maintenance processes may be time consuming and inefficient, as the beam-line component is not being used. As such, frequent maintenance processes may decrease the time available for IC production, thus increasing overall manufacturing cost.